Auscultation is typically used as a diagnosis tool in medicine, in particular for the diagnosis of cardiovascular disease. Auscultation relies on correctly determining which of the primary heart sounds correspond to the systolic phase of the heart and which sounds correspond to the diastolic phase of the heart. Learning auscultation may be difficult. The skill relies on detecting the correct sequence of brief events that occur close in time, a skill that is often difficult for human listeners. This is made more difficult when the systolic and diastolic intervals become more equal, such as typically occurs at elevated heart rates.
Auscultation training is available. For example, recordings of heart sounds, i.e. phonocardiograms (PCGs), that emphasis various pathological conditions exist. Many of these recordings are processed to emphasize particular features, such as enhancing a mid-systolic click to better distinguish the features of mitral valve prolapse. The recordings are also typically processed to reduce background noise commonly found in clinical practice, such that a physician new to clinical practice may have difficulty recognizing the distinguishing sounds in a clinical setting. Alternatively, training systems that use simulated heart sounds exist. Some of the simulated sounds, however, may seem unnatural to a trained physician or, as simulated, may not be physiologically feasible. Furthermore, teaching auscultation typically relies on memorization of heart sound patterns related to a particular pathophysiological condition. For example, memorizing the acoustical features of aortic stenosis.
Additionally, diagnostic instructional manuals rely on subjective descriptions of heart sounds, such as “musical” or “blowing” sounding murmurs, which require practice to appreciate. Furthermore, the practice and teaching of the clinical skill of auscultation of the heart has declined among physicians, partly due to a reliance on echocardiography testing. Recent studies have concluded that physicians can reliably identify only a small number of standard heart sounds and murmurs. Consequently, serious heart murmurs may go undetected by physicians.